Answer
$\text{pH} = -\log_{10}[\text{H}^+]$ and $\text{pH} + \text{pOH} = 14$ (since $K_w = [\text{H}^+][\text{OH}^-] = 1.0 \times 10^{-14}$).
Explanation
A neutral solution at $25^\circ\text{C}$ has $\text{pH} = 7$; acidic solutions have $\text{pH} < 7$ and basic solutions have $\text{pH} > 7$.